MD 1484 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR PORTIONS OF NE…SOUTHEASTERN SD…AND NORTHWESTERN IA
Mesoscale Discussion 1484
NWS Storm Prediction Center Norman OK
0209 PM CDT Mon Jul 10 2023
Areas affected...Portions of NE...southeastern SD...and northwestern
IA
Concerning...Severe potential...Watch likely
Valid 101909Z - 102115Z
Probability of Watch Issuance...80 percent
SUMMARY...The area is being monitored for increasing severe-storm
potential this afternoon. A severe thunderstorm watch will likely be
needed in the next hour or two.
DISCUSSION...Latest surface observations indicate a
northeast-southwest-oriented pre-frontal trough/wind shift extending
from southeastern SD into northern NE. Along the wind shift in SD,
strong surface heating amid upper 60s to lower 70s dewpoints is
supporting a locally uncapped air mass and isolated thunderstorm
development. While weak large-scale ascent over the surface boundary
casts uncertainty on storm coverage, around 40-50 kt of effective
shear (characterized by a long/straight hodograph) will
conditionally support organized storms including supercells this
afternoon into the evening. The weak large-scale ascent and
deep-layer shear vectors oriented perpendicular to the boundary
should favor discrete/semi-discrete supercells initially, with a
risk of large hail (some up to 2 inches in diameter) and locally
damaging gusts. With time, localized clustering will be possible
owing to storm splits/mergers, and the severe-wind risk could
increase as a result. A severe thunderstorm watch will likely be
needed in the next hour or two.
..Weinman/Mosier.. 07/10/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DMX...FSD...OAX...GID...LBF...GLD...
LAT...LON 40020053 40100100 40540143 41030146 41350135 41710099
41940070 42200030 42479990 42869926 43079872 43359798
43469743 43549677 43479607 43449554 43289507 42949483
42509490 42109523 41689577 41129679 40679789 40059974
40020053
